Respiratory viral infections have a major impact on public health. Acute respiratory infections largely caused by viruses, are the most common illnesses experienced by otherwise healthy adults and children. Among the respiratory viruses, influenza viruses are known to cause outbreaks globally. Information on the activity of influenza virus in our country is limited and none from Chennai. The present study was carried out to isolate and identify the influenza virus serotypes causing acute respiratory infection in children attending a tertiary care centre at Chennai.